This invention relates generally to the field of connecting tubular members together to form a confined passage, such as a pipeline. More specifically, this invention relates to an apparatus and method for securing connectors or collars on the ends of tubulars for connection of the tubulars end to end to form a conduit, such as a pipeline, particularly in underwater conditions.
In offshore oil recovery operations, the wellhead is typically on the seabed and oil is distributed to a production platform or collection facility through a submerged pipeline. Joining together submerged pipeline members or repairing submerged pipelines is difficult to do employing conventional welding techniques or other customary procedures. This problem is addressed by a variety of mechanical connectors which are available to secure the ends of pipeline sections together below the water surface without welding. These devices typically secure the ends of pipe together by connectors which mechanically grip the pipe ends. Effecting a complete seal about the pipe ends utilizing such connectors is difficult and time consuming, often requiring divers to perform relatively complicated and time consuming procedures under water to join the pipe ends together.
Another problem associated with conventional mechanical connectors is that some such connectors require internal pipe gripping devices. Such internal devices are undesirable because frequently they interfere with devices run through the pipeline which require an unrestricted internal pipeline passage. For many applications, internal restrictions in the pipeline are unacceptable.
Generally, conventional underwater pipe connectors have been difficult and expensive to use, and the pipeline segments made with such conventional connectors are in many instances prone to failure.
It is therefore an object of the present invention to provide an apparatus and method for effecting underwater connection of pipe ends by cold forging a connection collar or flange fitting on the end of a pipe.
It is another object of the present invention to provide an apparatus for forging the end of a pipe into a collar or other pipe fitting which may be remotely operated.
It is yet another object of the present invention to provide a pipeline connector which does not restrict the internal pipe passage.
It is still another object of the present invention to provide an apparatus for cold forging a pipe fitting on a pipe end by reciprocating a plurality of rollers driven by hydraulic pressure along the internal surface of the pipe to force the pipe end laterally outwardly for sealing engagement with the pipe fitting.
In a preferred embodiment of the invention, pipe joints are connected together by cold forging the ends of the pipe joints laterally outwardly into a surrounding collar or flange fitting for connecting pipe joints together to form a pipeline. The forging apparatus of the invention is hydraulically operated to reciprocate a plurality of rollers along the inside of the pipe joint for expanding the end thereof into a surrounding collar or flange fitting. The rollers are carried on a shaft which includes a tapered portion cooperating with the rollers to force the rollers radially outwardly to forge the pipe end into the flange collar. The forging apparatus is provided with a gear mechanism which incrementally rotates the rollers upon completion of each reciprocal pass so that substantially all of the internal surface of the pipe end is contacted by the rollers to forge the pipe end into the surrounding flange collar.
The foregoing features, advantages and objects of the invention, as well as other features apparent to those skilled in the art, will be more fully described and understood by reference to the following drawings, specification and claims.